With advances in technology, the portable projection apparatus is getting more compact and lightweight in response to the demands from users. However, it is quite important for portable projection apparatus to develop a mean to eliminate system noise generated by the portable projection apparatus due to the distance between a portable projection apparatus and a user is relatively small while the portable projection apparatus is being used.
In addition, the position and quantity of heat-dissipating fans in the portable projection apparatus are limited due to that portable projection apparatus has a relatively smaller size. Further, it is understood that when the brightness of the projection apparatus is higher, the energy inputting into the light source is higher. Consequentially, the generated heat is increased. A portable projection apparatus may require a higher heat dissipating effect to decrease the temperature of the portable projection apparatus if the internal heat is higher. In general, when the rotational speed of fan is higher, the heat dissipating effect of the portable projection apparatus is better, however, a large noise is accompanied.
The information disclosed in this “BACKGROUND OF THE INVENTION” section is only for enhancement understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Furthermore, the information disclosed in this “BACKGROUND OF THE INVENTION” section does not mean that one or more problems to be solved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art.